DSS became operational on October 1, 1972. Prior to the formation of DSS, the Personnel Security Investigation mission was accomplished by the military services. When DSS inherited the PSI responsibilities, prior investigations became their property. However, due to lack of storage space, old files remained in the military services file repositories until requested on an individual basis by DSS. As a result, most of these investigations were destroyed at the end of their routine retention period.
In addition, the large majority of DSS investigative files for field investigations are retained only for 15 years after the closing date of the last investigative effort. Therefore most DSS investigations with a last investigative effort closing date of 15 years or more have been deleted from their files. So having to process a new investigation is a requirement if it has been in excess of 24 months since you have been actively indoctrinated onto a classified contract. Some exceptions apply, but be prepared to fill out a new SF 86 Form for processing.